Currently, there are known electromechanical locks, operation of which is based on a lock code, using an electronic card or key, thereby activating a mechanical system that performs the opening or closing of the door wherein the lock is installed.
This installation or system is mounted within the knob or knobs of the door cylinder involved in the lock assembly, resulting in a significant limitation of space.
Moreover, current clutch systems that are mounted in conventional locks require, for their operation, electric motors of large size in order to actuate the clutch mechanism itself. Logically, this implies a waste of space, both that occupied by the motor and that occupied by the clutch system. Furthermore, the known and forced arrangement of limit switch detectors results in that the space required have to be even greater.
In short, the clutch mechanisms applicable to existing electromechanical locks imply a remarkable space occupation, which obviously affects an increase of the volume corresponding to the assembly making up the clutch mechanism associated with the electric drive motor.
On the other hand, there is known the patent ES2331865B1 (of the same applicant as the present invention) consisting of a clutch mechanism applicable to electromechanical lock cylinders comprising a cylinder mounted on the lock inside and axially including a rotor carrying the corresponding clutch means on the basis of which is susceptible to be interlock with a clutch disc on which the cam, rotation of which causes the actuation of the lock latch and/or bolt, is fixed.
It is characterized in that the clutch means are formed from a cart axially movable by actuating a spindle coupled at the output of the electromagnetic motor; with the particularity that on one of the valleys of the spindle one of the branches of an “U”-shaped resilient member is positioned, of unequal side branches and located in a housing provided on the inner face of the base body that forms part of the cart itself, in combination with a lid attached to said base through suitable screws; with two springs being provided in the base and in lid of the axially arranged cart, which by one end are support on the inner face of the lid itself, while by the other end are partially housed in end housings belonging to the clutch pins susceptible to occupy an inoperative and withdrawal position to the rotor lid, or an operating and emerging position, passing through holes provided in the corresponding clutch disc to which the cam is fixed for actuating the lock latch and/or bolt; with the further particularity that the cart is prevented from rotating by means of a pair of rods emerging from the inner face of the rotor lid, said rods further constituting a guiding means with minimum friction in the axial displacements of the cart.
A first problem with the patent ES2331865B1 is that if a user is applying a torque to the knob against the lock mechanisms, the clutch pins are disposed between the rotor lid and the clutch disc, failing to be removed. The cart cannot be removed either, whereby the spindle and the motor are blocked. This blockage is detected by the motor circuit; the detection is done by increasing the power consumption, resulting in the disconnection of the motor itself during a split second operation, for then trying again to repeatedly disengage the cylinder until there is no cause of blockade.
The problem is that if the user is maintaining the torque for a long time without being able to release the clutch pins, the consumption of the motor increases, due to repeated connections and disconnections of the motor and, therefore, the life battery of the motor shortens.
Likewise, a second problem that the cart has is that the resilient member has a poor performance. This is because, on the one hand, the greater branch of the “U”-shaped resilient member is subjected to a double recess at its ends, meaning that the deformation experienced by that greater branch is very small, which in addition to reduce the performance involves a correct design of the position of the resilient member in the base body of the cart in order to ensure the contact between said branch and the spindle in its extreme positions. Furthermore, the power load of a resilient member is proportional to the length of the wire, being in this case very limited because the length of wire would only be the grater branch of the resilient member.